Brake



E. D. MACKINTOSHB BRAKE.

APPLICATION FILED JULY 24. 1918.

Patented July 20 192% ENVENTOR J K w m wi U JKMQ EDWARD D. MAOKINTOSH, 0F BROOKLYN, COMPANY, OF NEW YORK, N. Y., A 00 NEW YORK, ASSIGNOR TO S. S. HEPWOETI-I RPORATION OF NEW YORK, AND EDITH M.

MAOKINTOSH, OF BROOKLYN, NEW YORK.

BRAKE.

Application filed July 24, 1918.

T 0 all whom it may concern.

Be it known that I, EDWARD D. MACKIN- TOSH, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented a new and useful Improvement in Brakes, of which the following is a specification.

My present invention is an improvement on a former one, Patent N 0. 890,672, dated June 16, 1908. Its object is the fixing and maintaining, more or less uniformly, of some certain frictional strength of the brake form of my previous invention.

Referring to the accompanying drawings, forming part of this specification:

Figure l is a general view of my improved brake,

Fig. 2 is an enlarged detail of the new improvement.

Two bands a, bear on a drum 6 and are connected, at one end of each, to two anchorages 0. The other ends of the bands are pivoted to the short arms of two levers 03. These levers have their fulcrums at 6. Their long arms are connected by a toggle consisting of a link f pivoted to another link made up of a rod 9, end pieces 72. and i, and a spring Z. The end pieces are pivoted to the long arms of the levers (Z. The end piece it is fixed to the rod but the end piece 2' slides upon it, the rod passing through holes at j and 7c and through a spring Z. This spring is confined in an opening in the end piece 2'- and bears on it, at m, and on a nut n that is threaded on to the rod. By virtue of the construction described the toggle, taken as a whole, is elastic, for it becomes longer when under sufiicient tension to shorten the spring and draw the nut away from the end piece at 0.

In operation the nut is so located on the rod that, when the bands are hard against the drum, and the two links of the toggle are in the relative POSlillC-DS shown, there will be a slight space between the nut and the end piece, at 0. WVith the nut so located. the spring is so made as to be under compression and is tending to shorten the toggle and to force the hands into hard contact with the drum by swinging the levers about their fulcrums. The spring thus determines the pressure of the bands upon the drum and tends to maintain this pressure,

Specification of Letters Patent.

Patented July 20, 1920. Serial No. 246,600.

and the resulting friction between the bands and the drum, more or less uniformly, when the bands wear away.

Without the elastic toggle the friction would fall off very greatly with a slight wearing away of the bands.

To change the location of the nut, on the rod, and thus restore space between it and the end piece at 0, when the bands do wear away, the pivot pin p is first removed from its place, and the end piece it is then separated from the lefthand lever 03, the rod 9 is turned in the nut n, and the parts are reassembled.

Having so located the nut, on the rod, that there will be a slight space 0 between the nut and the end piece i, the tension of the bands, and the resultant friction between the bands and the drum, will depend on the strength of the spring and the spring will tend to maintain such tension when the bands wear away slightly whereas, with the construction disclosed by my patent above specified the tension falls off greatly with only very slight wear. Moreover, with the old construction, there is no way of predetermining what the tension will be while, with the new construction, it will always correspond with the ten sion of the spring, and this can be predetermined.

I claim:

1. A brake drum, two bands secured. at one end of each, to two anchorages at diametrically opposite sides of the drum and bearing on the cylindrical face thereof, two levers pivoted and secured to the other ends of the bands, and an elastic toggle, includ ing a coil spring under compression, connecting the two levers and forcin the bands against the drum by swinging the levers on their fulcrums.

2. A brake drum, two bands secured, at one end of each, to two anchorages at diametrically opposite sides of the drum and bearing on the cylindrical face thereof, two levers pivoted and secured to the other ends of the bands, and an elastic toggle, of ad justable length, including a coil spring under compression, connecting the two levers and forcing the bands against the drum by swinging the levers on their fulcrums.

D. MACKINTGSH. 

